Merck’s therapeutic antibody Pembrolizumab, marketed as Keytruda, has won U.S. Food and Drug Administration approval as a treatment for refractory classical Hodgkin lymphoma.
The approval was based on data in 210 patients from the KEYNOTE-087 trial. The clinical trial showed an overall response rate with KEYTRUDA (200 mg every three weeks) of 69 percent (95% CI: 62, 75) with a complete remission rate of 22 percent and a partial remission rate of 47 percent.
Pembrolizumab was approved by the FDA in 2015 for the treatment of metastatic non-small cell lung cancer in patients whose tumors express PD-L1 and who have failed treatment with other chemotherapeutic agents. It was previously approved in 2014, under the FDA Fast Track Development Program, for use following treatment with ipilimumab, or after treatment with Ipilimumab and a BRAF inhibitor in advanced melanoma patients who carry a BRAF mutation.
Dr. Roger M. Perlmutter, president, Merck Research Laboratories, said:
“The results from KEYNOTE-087 showed that most patients with relapsed or refractory classical Hodgkin lymphoma responded to treatment with KEYTRUDA, and 22 percent experienced complete remission. Today’s approval – the first for KEYTRUDA in a hematologic malignancy – reinforces the hope that immunotherapy will prove useful in a wide variety of cancers.”
Dr. Craig Moskowitz, clinical director, division of hematologic oncology, Memorial Sloan Kettering Cancer Center, said:
“For the patients with classical Hodgkin lymphoma who are not cured with existing treatments, there are limited options, and treating their disease becomes more challenging. This approval is an important step forward in treating these patients, who are generally young and have a particularly poor prognosis, and gives us the opportunity to help patients in their fight against this devastating disease.”
Pembrolizumab binds to and blocks the programmed cell death 1 receptor located on lymphocytes. This receptor is generally responsible for preventing the immune system from attacking the body’s own tissues; it is a so-called immune checkpoint. Many cancers make proteins that bind to PD-1, thus shutting down the ability of the body to kill the cancer on its own.
Pembrolizumab competes with Bristol-Myers Squibb’s Opdivo, among others, in this space.